反应详情

To a mixture of triethyl orthoformate (70 mL) and acetic anhydride (70 mL) was added 3-amino-6-bromo-pyrazine-2-carboxylic acid methylamide (12.7 g, 55 mmol; see Example 16 (b) above) with stirring. The resulting solution was heated at reflux for 2 hours and allowed to cool to room temperature. The precipitate that formed was collected, washed with ethyl acetate, and dried to afford 6-bromo-3-methyl-3H-pteridin-4-one as a white solid (11.8 g, 89%). 1H NMR (300 MHz, DMSO-d6) δ3.54 (s, 3H), 8.70 (s, 1H), 9.15 (s, 1 H); 13C NMR (100 MHz, DMSO-d6) δ34.03, 133.28, 137.82, 152.39, 152.70, 153.33, 159.19.

1. temperatureThe resulting solution was heated
2. temperatureat reflux for 2 hours
3. customThe precipitate that formed
4. customwas collected
5. washwashed with ethyl acetate
6. customdried